Blend of ionic (co)polymer resins and matrix (co)polymers

ABSTRACT

The invention relates to polymeric resin blends containing polyelectrolyte resins blended into a polymer or copolymer matrix. Specifically, the polyelectrolyte resins are (co)polymers without hydrolyzable groups. The matrix polymer is a tough, and highly chemical-resistant (co)polymer, preferably a fluoropolymer. The polymeric resin blend is useful for forming films, and especially films useful for MEAs for use in fuel cells.

This application is a divisional application of U.S. patent applicationSer. No. 11/409,648 and claims priority benefit under 35 U.S.C. §119(e)of U.S. provisional application 60/684,038, filed May 24, 2005, and alsoclaims benefit under 35 U.S.C. §121 of U.S. patent application Ser. No.11/409,648, filed Apr. 24, 2006.

FIELD OF THE INVENTION

The invention relates to polymeric blends containing polyelectrolyteresins blended into a polymer or copolymer matrix. Specifically, thepolyelectrolyte resins are (co)polymers without hydrolyzable groups. Thematrix polymer is a tough, and highly chemical-resistant (co)polymer,preferably a fluoropolymer. The polymeric resin blend is useful forforming films, and especially films useful for MEAs for use in fuelcells.

BACKGROUND OF THE INVENTION

Perfluorocarbon ionic exchange membranes provide high cation transport,and have been extensively used as ionic exchange membranes. Polymericion exchange membranes can be referred to as solid polymer electrolytesor polymer exchange membranes (PEM). Because of the severe requirementsfor fuel cell applications, the most commonly used membranes, andcommercially available, are made from perfluorosulfonated Nafion®,Flemion® and Aciplex® polymers. However, reports and literature describethese membranes as working well but show several limitations thatprevent developing the technology further to commercialization.Additionally, they work better with gaseous fuels than with liquid fuelswhich may be mainly due to liquid fuel crossover that diminishes cellperformance. A membrane's chemical resistance and mechanical strengthare important properties for fuel cell applications. Indeed, themembrane is often subjected to high differential pressure,hydration-dehydration cycles, as well as other stressful conditions.Also, mechanical strength becomes important when the membrane is verythin such as less than 50 microns. Further, when used with fuel cells orbattery applications, the membrane sits in a very acidic medium attemperatures that can reach 200° C., in an oxidizing and/or reducingenvironment due to the presence of metal ions and sometimes the presenceof solvents. This environment requires that the membrane be chemicallyand electrochemically resistant, as well as thermally stable.

Currently, many fluorine-containing membranes can suffer from one ormore of the following short comings:

i) high liquid and gas crossover through the membrane;

ii) heterogeneous blending between the fluorinated polymer and otherpolymers that leads to inferior properties;

iii) insufficient chemical resistance in the presence of some liquidfuels;

iv) poor electrochemical resistance;

v) lack of homogeneous distribution of sulfonated groups;

vi) poor mechanical properties; and/or poor thermal stability.

Polyelectrolyte polymer blends having small domain sizes, and a processfor producing such are described in US 2005077233. The polyelectrolytepolymer is a non-perfluorinated polymeric resin containing ionic and/orionizable groups and in particular sulfonate or phosphonate groups, witha fluoropolymer matrix. One problem with the disclosed polyelectrolytesis that those containing hydrolytically unstable groups, such as estersand acrylamides, tend to hydrolyze in harsh chemical environmentsleading to a loss of the ionizable functionality.

WO 99/67304 describes a new class of unsaturated compounds having afluoroether-substituted aromatic ring, and polymers formed from thesecompounds. One use for the polymers is as separators in electrochemicalcells.

There is a need for a membrane that overcomes the limitations for use infuel cell applications.

Surprisingly, it was found that polymer blends containing afluoropolymer and a polyelectrolyte having no hydrolyzable groups can beused to form membranes for electrochemical cells having a high level ofchemical resistance and mechanical strength.

SUMMARY OF THE INVENTION

It is an objective of the invention to provide polyelectrolytes havingexcellent proton conductivity, and chemical resistance.

It is a further objective of the invention to provide a membrane or filmwherein the polyelectrolyte is evenly distributed in a matrix polymer,such as a fluoropolymer, and where the domain size is very small.

It is a further objective to provide a well-defined polyelectrolyte thatis hydrolytically stable (non-hydrolyzable), involves relativelylow-cost starting materials, and can be formed with a minimal number oftransformations.

The objectives of the invention are achieved, in accordance with theprinciples of a preferred embodiment of the invention, by a polymerblend containing a fluoropolymer and a polyelectrolyte having nohydrolyzable groups. The domain size of the vinyl resin in thefluoropolymer matrix is preferably 500 nm or less.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Depicts a typical Membrane-Electrode Assembly, as described inExample 54.

DETAILED DESCRIPTION OF THE INVENTION

The terms polymer and (co)polymer, as used herein refer to polymersformed from one or more monomers. This includes homopolymers,copolymers, terpolymers and polymers formed from four or more monomers.Copolymer refers to both random and block copolymers, as well as graftcopolymers. Copolymer is also used to describe a polymer resembling acopolymer which is formed by the partial reaction/substitution of someof the side groups of a homopolymer, resulting in a polymer backbonehaving two or more different moieties as side chains.

The invention relates to polymeric resin blends containingpolyelectrolyte resins blended into a polymer or copolymer matrix.Specifically, the polyelectrolyte resins are (co)polymers withouthydrolyzable groups. The matrix polymer is a tough, and highlychemical-resistant (co)polymer, preferably a fluoropolymer.

The matrix polymer can be any of the polymers and copolymers describedas the matrix in US2005077233, incorporated herein by reference.Preferably, the polymer matrix contains at least one fluoropolymer. Thefluoropolymer can be a homopolymer or other type of polymer, and can bea mixture of fluoropolymers or a mixture of fluoropolymer with anon-fluoropolymer. Preferably, the fluoropolymer is a thermoplasticfluoropolymer and can form a polymer blend with the other components ofa formulation, including other polymers present. Preferably, thefluoropolymer is a poly(vinylidene fluoride) polymer such as apoly(vinylidene fluoride) homopolymer. Other examples of fluoropolymersinclude, but are not limited to, a poly(alkylene) containing at leastone fluorine atom, such as polyhexafluoropropylene,polytetrafluoroethylene, poly(vinyl fluoride), or combinations thereof.More preferably, the fluoropolymer is a polymeric composition containingfrom about 30% to about 100 weight % of vinylidene fluoride and from 0%to about 70 weight % of at least one poly(alkylene) containing at leastone fluorine atom, such as, hexafluoropropylene, tetrafluoroethylene,trifluoroethylene (VF3), chlorotrifluoroethylene, and/or vinyl fluoride.Preferably, the molecular weight of the fluoropolymer which can includehomopolymers, copolymers, terpolymers, oligomers, and other types ofpolymers is from about 80,000 MW to about 1,000,000 MW and, morepreferably from about 100,000 MW to about 500,000 MW. The fluoropolymerscan be prepared using the techniques described in U.S. Pat. Nos.3,051,677; 3,178,399; 3,475,396; 3,857,827; and 5,093,427, allincorporated herein in their entirety by reference.

The matrix polymer is blended with one or more polyelectrolye(co)polymers. The polyelectrolyte copolymer contains ionic or ionizablegroups, as well as groups capable of crosslinking. The ionizable groupsare preferably sulfonate, phosphonate or carboxylate groups. The levelof ionic or ionizable groups should be high, preferably from 25 to 99weight percent, more preferably from 50 to 95 weight percent, and mostpreferably from 70 to 95 weight percent in the polyelectrolyte. Theionic or ionizable groups may be present on the monomer used to form thepolyelectrolyte, or may be added to the polyelectrolyte in apost-polymerization reaction.

The level of cross-linking moieties is from 1-75 weight percent,preferably 1-50 weight percent, more preferably from 10-30 weightpercent, and most preferably from 10-20 weight percent, based on theweight of the copolymer. Cross-linking can be done via conventionalmethods including, but not limited to, self-condensation, addition of asecondary cross-linking agent, or radiation crosslinking. These are welldescribed in the literature and well known in the art. Examples ofmonomers able to undergo self condensation crosslinking include, but arenot limited to: primary, secondary, and tertiary amines; N-methylolacrylamide; isobutoxy methacrylamide; N-methylenebisacrylamide; allylgroups, styryl groups; and glycidyl methacrylate. Examples of secondarycross-linkers include free and blocked isocyanates, melamines, epoxies,carboxylates, α,ω-dihaloalkanes, α,ω-dialdehydes, carboxylic acids,alkoxy silanes, silicones, aziridines, and carbodiimides. Catalystswhich can be chosen for the specific crosslinking chemistry and wouldinclude organotins, sulfonic acids, or amines. Examples of radiationcross-linking include electron beam, ultraviolet, and gamma radiation.

The polyelectrolyte may be non-perfluorinated, partially-perfluorinatedor entirely perfluorinated (co)polymers. The level of perfluorinationcan have dramatic effects on the ionic conductivity, mechanicalstrength, and permeability of the resultant (co)polymer blend(s).

Polyelectrolytes useful in the present invention are those containingnon-hydrolyzable groups. It has been found that monomers having readilyhydrolyzable groups, such as esters (for example acrylates andmethacrylates) and acrylamides, will hydrolyze in harsh chemicalenvironments (such as in battery acid), and lose the ability to easilyionize.

Preferred polyelectrolytes are those having a styrenic or vinyl etherstructure.

The polyelectrolyte can be formed by emulsion, suspension, inverseemulsion, or solution polymerization. It may also be formed by apost-polymerization modification.

The polyelectrolytes of the invention and manner of making thepolyelectrolytes will now be illustrated, both generally andspecifically, with reference to specific embodiments thereof, namelyvinyl ether-type polyelectrolytes, and styrenic-type polyelectrolytes.Also, specific and general embodiments will be illustrated showing bothtraditional copolymerization involving two separate monomers, and theformation of a copolymer based on partial reaction(s) of a homopolymersto form two or more separate functional monomer units.

Vinyl Ether-type Structures

The general structure of vinyl-ether-type polyelectrolyte structures ofthe present invention is:

Where:

-   L=non-perfluorinated alkyl or alkylene-etheralkylene-ether linkage    (DOUBLE listed)-   L′=a bond or alkyl or alkylene-etheralkylene-ether linkage (DOUBLE    listed)-   n=25-99 mol %, preferably greater than 50%, most preferably greater    than 70%-   m=1-75 mol %, preferably less than 50%, most preferably less than    30%-   A=a sulfonate, phosphonate or carboxylate-   B=a group capable of cross-linking

A general synthetic route to said copolymers is:

-   X=Cl, Br, or I-   Y=aliphatic (—CH₂—) of C₂ to C₁₂, or aromatic-containing (eg.:    —CH₂-Ph-CH₂—)-   M=Alkali earth metal (Li, Na, K, Rb, Cs)-   n:m=preferably, 80:20 or 90:10 mol/mol

An alternate general synthetic route to said copolymers is:

-   Z=aliphatic or perfluoroaliphatic of C₂ to C₅, or aromatic or    perfluoroaromatic-   MH=Metal hydride (eg. NaH)-   n:m=preferably, 80:20 or 90:10 mol/mol

Conditions for the transformation can vary. Typically, the poly(vinylalcohol) (PVA) is dissolved in DMSO, a basic reactant is added, such aspotassium hydroxide, sodium hydroxide, strongly basic amine, or metalhydride, then the sulfonated alkylhalide or sultone is added slowly withgentle heating (˜30 to 50° C.). Workup consists of precipitating thepolymer in an appropriate solvent with subsequent washing with solvent.

An alternative synthesis of a vinyl-ester type polyelectrolyte issimilar to the one above, however, the metal alkylsulfonate is used inthe tetraalkylammonium form. This promotes its solubility in organicsolvents other than DMSO as well as provides the final polymer as thetetraalkylammonium salt, which is advantageous for the furtherprocessing and blending with polyvinylidene fluoride (PVDF).

Conditions for the transformation of the alkylsulfonate areacidification of an aqueous solution of the starting Na salt to pH<0with HCl or H₂SO₄, evaporation to dryness, redissolution in minimalwater, and neutralization to pH>10 with the tetraalkylammoniumhydroxide.

In a variation, the PVA is converted first to the metal alcoholate form.This can be accomplished by the use of an appropriate metal hydride (eg.sodium hydride, lithium-aluminum hydride) in dry solvent (DMSO). Theformed metal alcoholate has increased reactivity over the alcohols inthe previous examples. The haloalkylsulfonate (in M⁺ ortetraalkylammonium form) or sultone can then be added to afford thedesired polymer.

In still another useful variation, the starting polymer is poly(vinylacetate) (PVAc), which, of course, is the precursor polymer topoly(vinyl alcohol). In this case, the ester is converted, in situ, tothe alcoholate and substitution on the haloalkylsulfonate happens all inone step. This has the advantage of more widely varying conditions asthe PVAc is much more soluble in organic solvents than the PVA. If thetetraalkylammonium form of the haloalkylsulfonate is used, the reactioncan be mostly homogeneous as the tetraalkylammonium salts are soluble incommon solvents.

In addition to PVA being used as the starting material for the abovetransformations, copolymers of vinyl alcohol(or acetate) can be used.This could be advantageous as incorporation of ethylene units, forexample, can assist with mechanical strength and durability. Styrenicstructures can also be formed by similar mechanisms by starting with anappropriate ester- or OH functionalized poly(styrene).

n:m>1:1 (mol/mol)

Z=bond, or aliphatic or aromatic linkerStyrenic-type Structures

The general structure of styrenic-type polyelectrolyte structures of thepresent invention is:

Where:

-   W=a bond, O, NH, S, SO, or SO₂-   Y=alkyl, aromatic, or alkylene-etheralkylene-ether linkage of C₁ to    C₁₂ [eg. (—CH₂—)₁₋₁₂]-   Z=a bond, alkyl, aromatic, or alkylene-etheralkylene-ether linkage    of C₁ to C₁₂-   n=1-99 mol %, preferably greater than 50%, most preferably greater    than 70%-   m=1-99 mol %, preferably less than 50%, most preferably less than    30%-   A=a sulfonate, phosphonate or carboxylate-   B=a group capable of cross-linking

Based on the general structure above, one can envision many routes tothese types of copolymers including, but not limited to(co)polymerization of the pre-functionalized monomers, andpost-polymerization modification of appropriately-functionalizedpolystyrenics. Some of the most preferred routes to these copolymers areoutlined below.

The direct copolymerization of Sodium 4-vinylbenzylsulfonate (NaVBS) andvinylbenzylalcohol (VBA) can be carried out. These particular monomersare synthesized as described in the literature. [NaVBS—U.S. Pat. No.2,909,508, VBA—Bamford, C. H., and Lindsay, H.; Polymer, 14, 330-332(1973).] Solution polymerization of these monomers can be carried out inan appropriate solvent (such as DMSO, NMP, DMF, DMAc and the like) usingstandard techniques. Copolymers of these monomers may also besynthesized in an emulsion, or inverse emulsion-type polymerization,although solution polymerization is preferred.

One method for synthesizing a sulfonated styrenic monomer containing asingle ether linkage, and useful in forming the polyelectrolyte of theinvention is shown below. VBC, a commercial product from Dow (SpecialtyMonomers division) is obtained as a mixture of the 3- and 4-vinylisomers. This molecule can be reacted with various alpha-hydroxy,alpha-amino, or alpha-sulfide, omega-sulfonate molecules to afford thenucleophilic substitution of the benzylic chloride position producing astyrenic-type monomer with variable spacers between the styryl unit andthe sulfonate.

Where VBC=4-vinylbenzyl chloride, mixture of 3- and 4-vinyl isomers

-   W═OH, NH₂, or SH-   Y=alkyl, aromatic, or alkylene-ether, alkylene-ether linkage of    C₁-C₁₂-   M=alkali earth metal (Li, Na, K, Rb, Cs) or tetraalkylammonium    counterion    The structure illustrated is obtained when: W═OH, and    Y═—CH₂—CH₂—CH₂—    The sulfonated styrenic monomer formed can then be copolymerized as    previously illustrated with a hydroxyl-functionalized styrenic    monomer to afford the desired copolymer structure.

The hydroxyl (or other cross-linkable) functionality on thepolyelectrolyte can be obtained from a hydroxyl functional monomer, asillustrated above. Alternately, appropriate ester-functionalizedmonomers may be employed during the (co)polymerization with a subsequentdeprotection (transformation) of the ester to the desired alcohol. This,coupled with one of the sulfonated monomer(polymer) syntheses describedabove will produce the desired final (co)polymer structure, as shownbelow.

Where:

-   W=a bond, O, NH, S, SO, or SO₂-   Y=alkyl, aromatic, alkyl-ether, or alkylene-ether linkage of C₁ to    C₁₂ [e.g. (—CH₂—)₁₋₁₂]-   Z=a bond, alkyl, aromatic, or alkylether, or alkylene-ether linkage    of C₁ to C₁₂-   R=alkyl or aromatic of C₁ to C₁₂-   n=1-99 mol %, preferably greater than 50%, most preferably greater    than 70%-   m=1-99 mol %, preferably less than 50%, most preferably less than    30%

The ester-containing comonomer need not even be styrenic in nature. Itonly need be copolymerizable with a sulfonated (or other functional)styrenic monomer.

In a similar manner, the sulfonate functionality need not beincorporated in the monomer component(s) prior to polymerization.Polymerization of an appropriately-functional monomer with subsequentsubstitution of the sulfonate unit will produce the final structure. Anexample that illustrates both of these routes (sulfonate substitutionand ester deprotection) is as follows:

Where:

-   W=a bond, alkyl, alkyl-aromatic, alkylether, or alkylene-ether    linkage C₁-C₁₂-   X=halide (Cl, Br, I)-   W′=W, where they need not be the exactly the same structure-   Y=a bond, O, NH, S, SO, SO₂-   R=alkyl or aromatic of C₁ to C₁₂-   R′=alkyl or aromatic of C₁ to C₁₂, not necessarily but can be the    same as R-   n=1-99 mol %, preferably greater than 50%, most preferably greater    than 70%-   m=1-99 mol %, preferably less than 50%, most preferably less than    30%

In one embodiment, where W═CH₂, W′=a bond, R═CH₃, X═Cl, Y═O, andR′═CH₂—CH₂—CH₂, the synthesis of the polyelectrolyte would be:

In one preferred embodiment, a copolymer polyelectrolyte of theinvention is synthesized from a single homopolymer by selectivefunctionalization to form the desired (co)polymer. The functionalizationstep must be very well controlled in order to produce the desired n:mratio in the final copolymer. For example:

Where:

-   W=alkyl, aromatic, alkylether, or alkylene-ether C₁-C₁₂-   W′=alkyl, aromatic, alkylether, or alkylene-ether C₁-C₁₂, but not    necessarily the same as W-   X=halide (Cl, Br, I)-   X′=halide (Cl, Br, I) not necessarily the same as X-   Y=alkyl or aromatic ester-   M=alkali earth metal (Li, Na, K, Rb, Cs) or tetraalkylammonium    cation

A specific example would be the following:

Where: W═CH₂, X═Cl, Y=acetate, X′═Br, W′=propyl, M=Na

In addition, the hydroxylated homopolymer can be formed by the directpolymerization of the analogous hydroxylated monomer. It need not beconverted from the halide-bearing monomer. The hydroxylated homopolymercan then be used as shown above to form the desired copolymer structure.

where: W=alkyl, aromatic, alkylether, or alkylene-ether C₁-C₁₂

Additional styryl-type monomers useful in the invention include, but arenot limited to a sulfobetaine, meaning the monomer contains a sulfonategroup as well as it's own counterion (quaternary ammonium). Forstyrylsulfobetaine-type monomers of the type shown below, thesubstitution need not be at the 2-position, and could potentially be atthe 3- or 4- or multiple positions. It is also possible that theammonium counterion be pendent to the ring, and not necessarily apyridinium type ion as shown in this example. Thehydroxyl-functionalized monomer shown is similar to those describedpreviously in this report. The above copolymer can be produced bytypical free-radical copolymerization in appropriate solvent as in theother systems and as is well known in the art.

Another embodiment of the invention would be a polyelectrolytecontaining a polymer or copolymer of an aromatic monomer having pendentfluorinated sulfonate groups. One example would be the monomer describedin WO 99/67304, incorporated herein by reference. Monomers of this type,have the general structure:

wherein R_(f) is a fluoroalkylene or fluoroalkylene-ether; Y is C, O, orN; and R_(f)′ is fluoroalkylene or fluoroalkylene-ether; and

wherein (R)_(m), is a polymerizable group, Br or I; and R_(f), R_(f)′,and Y are as described above. The aromatic monomers having pendentfluorinated sulfonate groups can be used to form homopolymers, or theycan be copolymerized with other ethylenically unsaturated monomers toform the polyelectrolyte of the invention. A preferred monomer for usein forming a copolymer is styrene. The (co)polymer is then blended intothe matrix polymer.

The polyelectrolyte is blended into a polymer or copolymer matrix toform the polymer blend of the invention. The polymer blend may be anytype of mixture of two or more polymers described above and throughoutthis application with at least one selected from the class of matrixpolymers and one selected from the class of polyelectrolytes.Preferably, the polymer blend is an intimate blend of chosen polymers.The amount of matrix polymer can be from 5 to 95 weight % and the amountof polyelectrolyte can be from 95 to 5 weight %. Preferably, the matrixpolymer is present in an amount of from 40% to 80 weight % and thepolyelectrolyte is present at from 20 to 60 weight %.

In many cases, the acid groups present on the polyelectrolyte phase areinitially in neutralized form. The cation may consist of any chosen fromGroup IA metals (Na, K, Cs, Rb), or alternatively an organic cation suchas phosphonium, imidazolium, or benzamidazolium. In order to effectivelycontinue the process of blending a polyelectrolyte of this inventionwith a matrix (co)copolymer, the sulfonic acid groups on thepolyelectrolyte must first be ion-exchanged (protonated) with protons.This is accomplished by passing a solution of the polyelectrolytethrough a column which has previously been loaded with an appropriateion-exchange resin. The column can be of a range of diameters andlengths depending on the quantity of polyclectrolyte to be treated. Atypical column will have a diameter of from 1.0 in. to 36.0 in.,preferrably from 6.0 in. to 18.0 in. The column length will have alength of from 12.0 in. to 144.0 in, preferrably from 24.0 to 72.0 in.The bottom of the column is conical-shaped and fitted with a stopcock orsimilar device to control the flow of liquid through the apparatus.

To afford the ion-exchange (protonation) of the polyelectrolyte, to thecolumn is added a quantity of ion-exchange resin. Dowex Marathon (DowChemicals, Inc.) ion-exchange resin is one example of a classes ofresins which may be used. In particular, Dowex Marathon A, Marathon B,or Marathon C resins may be used. The amount of resin loaded into thecolumn is equivalent to at least one to ten times in relation to thenumber of acid groups to be ion-exchanged (per the manufacturer'sspecifications). Preferrably, the amount of resin used is from one tofive times in relation to the number of acid groups to be ion-exchanged.The column is then washed with deionized water several times until thewater eluting from the column is no lower than pH=5.0. The neutralizedpolyclectrolyte is then dissolved in an appropriate solvent to ahomogeneous solution. The solvent should be chosen according to thespecific chemical functionality present in the polyelectrolyte.Typically, polar protic or polar aprotic solvents are used. Thepolyelectrolyte solution is added to the top of the column and allowedto drain into contact with the exchange resin. Additional solvent isadded to the top of the column in an amount enough to keep the resinfrom drying out. The pH of the eluting solution is continuallymonitored. The protonated polyclectrolyte solution is collected from thebottom of the column when the pH of the eluting solution drops below5.0. The polyelectrolyte solution collection is stopped when the pHreturns to above 5.0. A protonated polyelectrolyte solution is therebyobtained. The content of any residual cation is quantified by analyticaltechniques familiar to those skilled in the art.

In a preferred embodiment, the blending process is begun by firstreacting the acidic proton-bearing ionizable groups on thepolyelectrolyte with an appropriate tetraalkylammonium hydroxide (TAAOH) to form the tetraalkylammonium salt. Preferably the ammonium salthas a molecular weight of at least 186. Examples of suitable ammoniumsalts include: tetramethylammonium, tetraethylammonium,tetrapropylammonium, tetrabutylammonium, tetrapentylammonium, andtetrahexylammonium.

A solution of this TAA-neutralized polyelectrolyte may thensolvent-switched to a solvent which may appropriately dissolve thematrix (co)polymer of choice. If the solvent that was used in theion-exchange column and for the TAAOH neutralization also will dissolvethe matrix (co)polymer, this step will not be necessary. A preferredembodiment includes the ‘switching’ of solvent from that which theion-exchange column was run to another which the TAA neutralizedpolyclectrolyte and the matrix (co)polymer are both fully soluble. Thisprocess preferrably consists of adding the new solvent to the TAAneutralized polyelectrolyte solution then removing the original solventwith heating and application of vacuum (vacuum distillation). Otherprocesses for affording this ‘solvent switch’ include precipitation ofthe TAA-neutralized polyelectrolyte with subsequent filtration of thepolymer and redissolution in the new solvent. Once all of the originalsolvent has been removed, an appropriate amount of matrix (co)polymer,which has previously been dissolved in the same solvent is added. Asstated above, the amount of matrix polymer can be from 5 to 95 weight %and the amount of polyclectrolyte can be from 95 to 5 weight % in theblend solution. Preferably, the matrix polymer is present in an amountof from 40% to 80 weight % and the polyelectrolyte is present at from 20to 60 weight % in the blend solution. This blended solution is then castinto a thin film or further processed to yield a useful article such asan ion-exchange membrane.

Casting of the blended solution can be carried out by many differentprocedures familiar to those skilled in the art. Particularly, solutioncasting with heating is selected. A quantity of the polymer blendsolution is placed on an appropriate substrate. A sharp metal knife isthen drawn across the substrate with a gap between the knife and thesubstrate. The thickness of this gap and the viscosity of the polymerblend solution control the thickness of the formed film. The thicknessof the formed film is dependent on the end-use of the material, and canvary from 1.0 μm to 2.0 mm. Preferrably, the formed film has a thicknessof 10.0 μm to 500.0 μm and most preferrably from 20.0 μm to 250.0 μm.This ‘wet’ film is then dried in a air-circulating oven at elevatedtemperature. The time and temperature for drying the film can varywidely. The temperature used is from 20° C. to 250° C., preferrably from100° C. to 220° C., and most preferrably from 120° C. to 200° C. Thedrying time for the wet film can also vary widely. The oven residencetime should be commercially applicable and scalable in that it can befrom 1.0 s to 24 h, preferrably from 1.0 min. to 2.0 h, and mostpreferrably from 1.0 min. to 45.0 min.

The thickness of the final, dried film depends on the original thicknessof the wet film before drying. This thickness will vary depending on theapplication intended for the final atricle. The thickness can be from1.0 μm to 2.0 mm, preferrably from 5.0 μm to 500.0 μm, most preferrablyfrom 10.0 μm to 300.0 μm. The dried film is removed from the substrateby typical methods familiar to those skilled in the art. Typically, thefilm is mechanically peeled from the substrate directly or with the aidof a metal knife. Alternatively, the film can be hydrated or submersedin water or solvent to aid in the removal of the film from thesubstrate.

The domain size of the polyelectrolyte in a cast film should bepreferably less than 1.0 μm, and more preferably between 1 nm to 500 nm.The domain sizes discussed herein are with respect to maximum domainsizes and/or average domain sizes. In a preferred embodiment, the domainsizes recited are the maximum domain sizes, but can be the averagedomain sizes.

The proton conductivity of the polymer blend of the invention is >20mS/cm, preferably >50 mS/cm, and most preferably >100 mS/cm.Additionally, the polymer blend has a high degree of mechanicalstrength, a low swelling when hydrated, hydrolytic (chemical) stability,and a low level of sulfur loss (if sulfonated) in hot water or hot acidenvironments.

An article, such as a membrane, produced from the polymer blend of theinvention can then be used as-is or further treated by an acidic washingstep to remove the tetraalkyl groups, concurrently reprotonating theionizable groups present on the starting (co)polymer component. Inaddition, cross-linking may be employed to improve dimensinal stability.Cross-linking may be carried out by the action of an external agent onpendent functionalities present on the polyelectrolyte, the matrix(co)polymer, or combinations thereof. It is also feasible to incorporateinternal cross-linking groups which are already pendent on either thepolyelectrolyte or the matrix (co)polymer, which are then appropriatelyactivated by application of an external impetus (heat or radiation).

Due to the various advantages described above, the applications of thepresent invention can include, but are not limited to, films, membranes,fuel cells, coatings, ion exchange resins, oil recovery, biologicalmembranes, batteries, and the like. The resultant articles can beutilized as perm-selective membranes for battery or fuel cellapplications. In addition, the resultant articles may be applied toelectrodes for the construction of a membrane-electrode-assembly, may beimbibed with various liquids, or may be introduced onto or into areinforcing matte or porous web to increase mechanical integrity.

A polymeric ion membrane or polyelectrolyte membrane can be made fromthe polymer blend of the present invention. The formed film or membranemay be used as a single layer, or may be part of a multi-layer film ormembrane. The polymeric ion membrane can be prepared from conventionalfilm preparation methods, such as melt extrusion, solvent cast, latexcast, and the like. Membrane electrode assemblies can be made from themembranes of the present invention and fuel cells using this membraneelectrode assembly can be prepared. In using the polymers of the presentinvention to form membranes, the polymer can have any equivalent weight(g of acid groups per g of total polymer) and preferably has anequivalent weight of from about 200 to about 8,000, and preferably fromabout 200 to about 1,500 and even more preferably from about 200 toabout 1,400, with respect to the polyelectrolyte present in the polymerblend.

In more detail, the compositions of the present invention are especiallyuseful in fuel cells, batteries, and the like. The design and componentsused in the fuel cell and batteries would be the same as in conventionalfuel cells and batteries except using the compositions of the presentinvention in the formation of the polymeric ionic exchange membrane.Accordingly, the designs and manners of making the fuel cells andbatteries as described in U.S. Pat. No. 5,795,668, EP 1 202 365 A1, PCTPublication No. WO 98/22989, WO 02/075835, and WO 98/20573, Lin et al.,Journal of Applied Polymer Science, Vol. 70, 121-127 (1998) can be usedin the present invention and are fully incorporated herein in theirentireties by reference. The membrane can be used alone or withconventional fillers, such as silica and the like. The fuel cell may usea liquid or gaseous fuel such as a liquid hydrocarbon like methanol orgas like hydrogen. The fuel cell of the present invention is capable ofoperating at a wide range of operating conditions. The fuel cell of thepresent invention can have a porous support layer and an ion exchangeresin wherein the ion exchange resin is supported on at least one sideof the porous support layer. The present invention can be useful inhydrogen, direct methanol, or other fuel cells. Preferably, the fuelcells of the present invention have low fuel crossover, high protonicconductivity, and/or high mechanical strength. The thickness of themembrane can be conventional but is preferably from about 0.5 to about10 mils and more preferably from about 0.5 mil to about 5 mils. Further,the membrane preferably has an equivalent weight of from about 200 toabout 2500, and more preferably about 200 to about 1400. The poroussupport layer can be made from any conventional material such as afluoro-containing polymer or other hydrocarbon containing polymers suchas polyolefin. The porous support layer has conventional parameters withrespect to pore diameter, porosity, and thickness. The fuel cells of thepresent invention preferably have excellent proton conductivity,chemical resistance and low gas cross-over, relatively high electricalresistance, and high protonic conductivity.

EXAMPLES Sulfoalkylated Poly(vinyl alcohol) Syntheses Example 1Sulfopropylated PVA (40% Sulfonated, Method 1)

5.0 g of poly(vinyl alcohol) (PVA) (99% hydrolyzed, Mw˜144 k, Aldrich)was dissolved in 200 mL of anhydrous DMSO at 90° C., then cooled to roomtemperature. Separately, 28.80 g (1.13 eq. to OH) of sodium3-bromopropane sulfonate (NaBPS) was dissolved in 100 mL of anhydrousDMSO under nitrogen. 3.0 g (1.1 eq. to OH) of sodium hydride (NaH) wasdissolved in 150 mL of anhydrous DMSO under nitrogen to form a slurry.The NaH slurry was quickly added under nitrogen to a 2 L round-bottomflask equipped with 250 mL addition funnel, mechanical stirrer, andseptum. The PVA solution was then charged into the addition funnel andadded slowly to the NaH slurry with rapid stirring. This mixture wasstirred for 1 h until gas evolution ceased. The NaBPS solution was thenquickly added, and the reaction mixture was stirred at room temperaturefor 18 h. 1.0 mL of 5.0 wt.-% aqueous hydrochloric acid was added, thenthe reaction solution was poured into 2 L of rapidly-stirred acetone. Anoff-white precipitate was filtered, washed with 500 mL of acetone, anddried in vacuo. (8.50 g, 40%) ¹H NMR (D₂O): δ 4.40-

3.80 (broad, 4.79H, backbone CH—O, propyl O—CH₂), δ 3.35-δ 3.15 (broad,2H, propyl CH₂—SO₃), δ 2.40-δ 2.20 (broad, 2H, propyl C—CH₂—C), δ 2.20-δ1.70 (broad, 4.82H, backbone CH₂).

Example 2 Sulfopropylated PVA (60% Sulfonated, Method 1)

The procedure as outlined in Example 1 of this section was followedexactly except that 43.33 g of NaBPS (1.7 eq. to OH) dissolved in 200 mLof anhydrous DMSO was used. (12.65 g, 59%) ¹H NMR (D₂O): δ 4.40-3.80(broad, backbone CH—O, propyl O—CH₂), δ 3.35-δ 3.15 (broad, 2H, propylCH₂—SO₃), δ 2.40-δ 2.20 (broad, 2H, propyl C—CH₂—C), δ 2.20-δ 1.70(broad, 3.23H, backbone CH₂).

Example 3 Sulfopropylated PVA (10% Sulfonated, Method 1)

The procedure as outlined in Example 1 of this section was followedexactly, except that 20.0 g of PVA dissolved in 300 mL of anhydrousDMSO, 15.46 g NaBPS (0.15 eq. to OH) dissolved in 200 mL of anhydrousDMSO, and 1.66 g (0.15 eq. to OH) NaH in 100 mL anhydrous DMSO was used.(26.5 g, 75%) ¹H NMR (D₂O): δ 4.40-3.80 (broad, 14H, backbone CH—O,propyl O—CH₂), δ 3.35-δ 3.15 (broad, 2H, propyl CH₂—SO₃), δ 2.40-δ 2.20(broad, 2.17H, propyl C—CH₂—C), δ 2.20-δ 1.70 (broad, 23.5H, backboneCH₂).

Example 4 Sulfopropylated PVA (100% Sulfonated, Method 2)

5.0 g of poly(vinyl alcohol) (PVA) (99% hydrolyzed, Mw˜144 k, Aldrich)was dissolved in 200 mL of anhydrous DMSO at 90° C., then cooled to roomtemperature. Separately, 13.90 g (1.00 eq. to OH) of propane sultone wasdissolved in 50 mL of anhydrous DMSO under nitrogen. 3.0 g (1.1 eq. toOH) of sodium hydride (NaH) was dissolved in 150 mL of anhydrous DMSOunder nitrogen to form a slurry. The NaH slurry was quickly added undernitrogen to a 2 L round-bottom flask equipped with 250 mL additionfunnel, mechanical stirrer, and septum. The PVA solution was thencharged into the addition funnel and added slowly to the NaH slurry withrapid stirring. This mixture was stirred for 1 h until gas evolutionceased. The propane sultone solution was then added over 15 min, and thereaction mixture was stirred at room temperature for 18 h. 1.0 mL of 5.0wt.-% aqueous hydrochloric acid was added, then the reaction solutionwas poured into 2 L of rapidly-stirred acetone. An off-white precipitatewas filtered, washed with 500 mL of acetone, and dried in vacuo. (20.2g, 95%) ¹H NMR (D₂O): δ 4.40-3.80 (broad, 2.66H, backbone CH—O, propylO—CH₂), δ 3.35-δ 3.15 (broad, 2H, propyl CH₂—SO₃), δ 2.40-δ 2.20 (broad,2H, propyl C—CH₂—C), δ 2.20-δ 1.70 (broad, 1.98H, backbone CH₂).

Example 5 SulfopropylatedPVA (70% Sulfonated, Method 2)

The procedure as outlined in Example 4 of this section was followedexactly, except that 25.0 g of PVA dissolved in 450 mL of anhydrousDMSO, 51.0 g propane sultone (0.80 eq. to OH) dissolved in 100 mL ofanhydrous DMSO, and 10.91 g (0.80 eq. to OH) NaH in 450 mL anhydrousDMSO was used. (106.8 g, 128% (DMSO impurity)) ¹H NMR (D₂O): δ 4.40-3.80(broad, 3.17H, backbone CH—O, propyl O—CH₂), δ 3.35-δ 3.15 (broad, 2H,propyl CH₂—SO₃), δ 2.40-δ 2.20 (broad, 2H, propyl C—CH₂—C), δ 2.20-δ1.70 (broad, 2.65H, backbone CH₂).

Example 6 SulfopropylatedPVA (50% Sulfonated, Method 2)

The procedure as outlined in Example 4 of this section was followedexactly, except that 20.0 g of PVA dissolved in 200 mL of anhydrousDMSO, 28.10 g propane sultone (0.50 eq. to OH) dissolved in 100 mL ofanhydrous DMSO, and 5.46 g (0.50 eq. to OH) NaH in 150 mL anhydrous DMSOwas used. (52.5 g, 99%) ¹H NMR (D₂O): δ 4.40-3.80 (broad, 3.83H,backbone CH—O, propyl O—CH₂), δ 3.35-δ 3.15 (broad, 2H, propyl CH₂—SO₃),δ 2.40-δ 2.20 (broad, 2H, propyl C—CH₂—C), δ 2.20-δ 1.70 (broad, 3.87H,backbone CH₂).

Example 7 Sulfobutylated PVA

The procedure as outlined in Example 4 of this section was followedexactly, except that 34.0 g of PVA dissolved in 350 mL of anhydrousDMSO, 85.0 g (63.6 mL) butane sultone (0.80 eq. to OH), and 19.47 g(1.05 eq. to OH) NaH in 250 mL anhydrous DMSO was used. (128.7 g, 103%(residual DMSO)) ¹H NMR (D₂O): δ 6.05-5.81 (broad m, 0.29H, allyl CH), δ5.25-δ 5.05 (broad m, 0.58H, allyl CH₂), δ 4.16-δ 3.40 (broad, 2.45H,backbone CH—O, butyl —O—CH₂), δ 3.10-δ 2.85 (broad m, 2H, butyl—CH₂—SO₃), δ 2.60-δ 2.40 (broad m, 0.59H allyl C═C—CH₂—), δ 2.10-δ 0.50.(broad, 5.42H, butyl —CH₂—CH₂—, backbone —CH₂—)

Sulfoalkylated Polystyrenic Copolymer Syntheses Monomer SynthesesExample 8 Sodium Vinylbenzyl Sulfonate (NaVBS), Procedure A

A solution of sodium sulfite (872.1 g, 6.919 mol, Aldrich) andtetrabutylammonium chloride (37.0 g, 0.133 mol, Fluka) in deionizedwater (6000.0 g, 6.00 L) was charged into a 22 L round-bottom flask andheated to 45° C. with mechanical stirring. Separately, vinylbenzylchloride (1000.0 g, 6.29 mol, Dow, 96% pure, 57% meta, 43% para) wasadded to a solution of sodium iodide (1037 g, 6.919 mol, Aldrich) inacetone (4740 g, 6.00 L), which was added to a 12 L round-bottom flaskand stirred at 40° C. for 0.25 h. The precipitate (NaCl) was removed byfiltration and washed with 200 mL of acetone. The filtered acetonicsolution was immediately added to the aqueous salt solution. Thetwo-phase mixture was stirred at 40° C. for 80 min. The acetone wasevaporated in vacuo. The remaining aqueous mixture was filtered to givewet sodium vinylbenzylsulfonate (NaVBS), as white paste. The paste wasdried in vacuo. (694 g, 50.1%) ¹H NMR (D₂O): δ 7.30-7.55 (m, 4H,aromatic), 66.80 (dd, 1H, vinyl), δ 5.87 (dd, 1H, vinyl), δ 5.33 (dd,1H, vinyl), δ 4.16 (s, 2H, benzyl).

Example 9 Sodium Vinylbenzyl Sulfonate (NaVBS), Procedure B

A 100 gal. glass-lined reactor was charged with 46.5 gal. of water and20.0 gal. of acetone at room temperature. To that mixture was added 18.0kg. of sodium sulfite, 1.0 kg. of sodium iodide, and 20.0 kg. ofvinylbenzyl chloride (Dow Specialty Monomers, 55% meta 45% para isomer).This mixture was sparged with nitrogen for 30 min. then heated to 50° C.and maintained at that temperature for 24 h. The acetone andapproximately 20 gal. of water were then removed by vacuum distillation.The remaining slurry was cooled to 10° C. and filtered, recovering alight yellow solid. The filtrate was returned to the reactor, and anadditional 15 gal. of water was removed by vacuum distillation. Thesolids were combined and dried in vacuo at 40° C. Recovered yield was13.1 kg (45%). ¹H NMR (D₂O): NMR data missing

Example 10 Vinylbenzyl Alcohol (VBA), Procedure A

Vinylbenzyl chloride (VBC, 90%, mixture of meta and para isomers,stabilized, 4.3 g, 25 mmol) was added to a mixture of potassium acetate(KOAc) (3.2 g, 33 mmol) in DMSO (11.0 g). The mixture was stirred at 40°C. for 2 h. A 5 mL sample of reaction mixture was withdrawn and added to10 mL of water. This solution was extracted twice with 20 mL of ethylacetate. Evaporation of the ethyl acetate yielded a yellow oil. ¹H NMR(DMSO-d6): δ 7.35 (m, 4H, aromatic), δ 6.70 (m, 1H, vinyl), δ 5.75 (d,1H, vinyl), δ 5.25 (d, 1H, vinyl) δ 5.07 (s, 2H, benzyl) δ 2.07 (s, 3H,methyl ester).

Ethanol (7 mL), DI water (36 mL), and NaOH (1.19 g, 30 mmol) were addedto the remaining reaction mixture, and refluxed for 1 h. Extraction with40 mL of EtOAc followed by drying over MgSO₄ and evaporation of thesolvent yielded a yellow oil (3.18 g, 99% yield). ¹H NMR (DMSO-d6): δ7.35 (m, 4H, aromatic), 66.70 (m, 1H, vinyl), δ 5.75 (d, 1H, vinyl), δ5.25 (d, 1H, vinyl), δ 4.65 (d, 2H, benzyl).

Example 11 Vinylbenzyl Alcohol (VBA), Procedure B

A 12 L, three-necked round-bottom flask was equipped with mechanicalstirrer, condensor, and thermocouple. To this flask was added 2.3 L ofglacial acetic acid, 663.0 g of potassium acetate, and 613.7 g ofvinylbenzyl chloride. This mixture was stirred at 110° C. for 18 h. Thinlayer chromatography was the used to determine the extent of thereaction. The product was extracted with 2 L of EtOAc (ethyl acetate)two times. The organic extracts were combined and washed with an aqueoussolution of NaHCO₃ (sodium bicarbonate) until neutral (ph˜7) and thenwashed again with 2 L of water. EtOAc was removed under reduced pressureto give 703 g of a light brown oil. (99% yield). ¹H NMR (DMSO-d6): δ7.35 (m, 4H, aromatic), δ 6.70 (m, 1H, vinyl), δ 5.75 (d, 1H, vinyl), δ5.25 (d, 1H, vinyl), δ 5.07 (s, 2H, benzyl), δ 2.07 (s, 3H, methylester).

A second 12 L flask equipped with mechanical stirrer, condensor, andthermocouple was charged with 761.0 g (13.56 mol) KOH (potassiumhydroxide), 3.5 L (86.6 mol) of MeOH (methanol), 1.1 L (58.38 mol) ofwater, and 703 g of vinylbenzyl acetate from the previous step producinga dark red-colored solution. The reaction was heated to reflux andfollowed by TLC, which indicated that the reaction was complete after 1hour. The reaction mixture was cooled to room temperature and extractedtwice with 4 L of diethyl ether. The ether layer was then washed withthree times with 4 L of aqueous sodium chloride, then two times with 4 Lof water. The ether layer was dried with MgSO₄ (magnesium sulfate) andfiltered. Ether was removed from the filtrate under reduced pressure togive a brown oil. (487.0 g, 91% yield) (94% overall). ¹H NMR (DMSO-d6):δ 7.35 (m, 4H, aromatic), δ 6.70 (m, 1H, vinyl), δ 5.75 (d, 1H, vinyl),δ 5.25 (d, 1H, vinyl), δ 4.65 (d, 2H, benzyl).

Example 12 4-(vinylphenyl)magnesium chloride (VP-MgCl)

A 250 ml 2-neck, round-bottom flask was charged with 2.5 g of magnesium(Mg) filings (0.14 mol), a stir bar, an addition funnel and a condenser.The Mg filings were stirred vigorously under nitrogen overnight. Asolution of 100 μL of 1,2-dibromoethane in 10 ml dry tetrahydrofuran(THF) was added to the Mg via syringe. This mixture was stirred at roomtemperature until it turned light brown. 13.85 g of 4-chlorostyrene (0.1mol) in 30 ml dry THF was added via the additional funnel over 1 hour,while maintaining the reaction temperature below 10° C. After all of the4-chlorostyrene was added, the mixture was warmed to room temperatureand stirred for an additional 30 min. The temperature was then increasedand the reaction was refluxed for 2 more hours. The reaction was cooledto 0° C. and used immediately for subsequent reactions.

Example 13 1-(4-Vinylphenyl)ethanol (1-VPE)

To a VP-MgCl solution as prepared in Example 12 of this section wasadded a solution of 4.84 g acetylaldehyde (0.11 mol) in 50 ml THF. Thesolution was added dropwise via addition funnel while maintaining thereaction temperature at 0° C. The reaction was then stirred for anadditional 1 h at 0° C. 60 ml of 2 M aqueous hydrochloric acid (HCl)solution was added via the addition funnel, maintaining the temperaturebelow 20° C. The reaction was filtered and extracted two times with 100mL of diethyl ether. The organic phases were combined, dried over MgSO₄and filtered. The diethyl ether was removed by vacuum evaporation atroom temperature. (13.6 g light yellow oil, 91.6%). ¹H NMR (DMSO-d6): δ7.40 (m, 4H, aromatic), δ 6.72 (m, 1H, vinyl), δ 5.82 (d, 1H, vinyl), δ5.23 (d, 1H, vinyl), δ 4.73 (q, 1H, CH—O), δ 1.35 (d, 3H, CH₃).

Example 14 2-(4-Vinylphenyl)ethanol (2-VPE) Make “Example 14A”

To a VP-MgCl solution as prepared in Example 12 of this section wasadded a solution of 4.84 g ethylene oxide (0.11 mol) in 50 ml THF. Thesolution was added via additional funnel over one hour, maintaining thereaction mixture at 0° C. Keep stir at 0° C. for one more hour after theaddition was finished. The reaction was then stirred for an additional 1h at 0° C. 60 ml of 2 M aqueous hydrochloric acid (HCl) solution wasadded via the addition funnel, maintaining the temperature below 20° C.The reaction was filtered and extracted two times with 100 mL of diethylether. The organic phases were combined, dried over MgSO₄ and filtered.The diethyl ether was removed by vacuum evaporation at room temperature.11.2 g white waxy solid, 75.7%). ¹H NMR (DMSO-d6): δ 7.20-δ 7.40 (m, 4H,aromatic), δ 6.72 (m, 1H, vinyl), δ 5.75 (d, 1H, vinyl), δ 5.23 (d, 1H,vinyl), δ 4.70 (t, 1H, OH), δ 3.65 (t, 2H, CH₂—O), δ 2.72 (t, 2H,CH₂—C).

(Co)Polymer Syntheses (Polymerizations) Example 14 Poly(NaVBS) Make“Example 14B”

A solution of sodium vinylbenzylsulfonate (20.00 g, 0.073 mol, 80% pure)in deionized water (266 g) was heated to 40° C. while stirring, and thensparged with nitrogen for 10 min. Vazo 56WSP (74 mg, 0.27 mmol, DuPont)was added toward the end of the sparging period. The reaction mixturewas heated to 85° C. and stirred for 24 h. The polymer was precipitatedinto acetone (2.25 L), and the liquid was decanted. Drying in vacuoyielded poly(sodium vinylbenzylsulfonate) (translucent plates, 14.55 g,91%). (GPC: Mw=91 k, PDI=2.2 vs. polyacrylic acid narrow standards), ¹HNMR (D₂O): δ 7.22 (broad, 2H, aromatic), δ 6.67 (broad, 2H, aromatic), δ4.15 (broad, 2H, benzyl CH₂), δ 0.30-2.55 (broad, 3H, backbone CH, CH₂).

Example 15 Poly(VBA)

10.0 g of vinylbenzyl alcohol (VBA) (74.6 mmol), 29.0 mL deionizedwater, 3.82 mL of aqueous 20.0 wt.-% sodium dodecyl sulfate (SDDS) (2.48mmol), 1.83 mL of aqueous 5.0 wt.-% sodium bicarbonate (NaHCO₃) (0.86mmol), and 1.83 mL of aqueous 5.0 wt.-% potassium persulfate (0.5 mol.-%to VBA) was added to a 100 mL round-bottom flask. This mixture wascooled to 0° C. for 1 h, after which 1.30 mL of aqueous 5.0 wt.-% sodiummetabisulfite (0.5 mol.-% to VBA) was added. The solution was spargedwith nitrogen for 15 min. The flask was closed with a rubber septum andplaced in an oil bath at 30° C. for 2.5 h. After that time, the polymerwas precipitated in 300 mL of methanol, filtered and dried in vacuo.(9.80 g, 98%), (GPC: Mw=80 k, PDI=4.0 vs. polyacrylic acid narrowstandards), ¹H NMR (DMSO-d6): δ 7.30-δ 6.10 (broad, 4H, aromatic), δ4.65-δ 4.25 (broad, 2H, benzylic CH₂), δ 2.20-δ 0.90 (broad, 3H,backbone CH, CH₂).

Example 16 Poly(VBC)

50.0 g of vinylbenzyl chloride (VBC) (Dow Specialty Monomers, 55% 3- and45% 4-isomer), 145.0 mL deionized water, 16.65 mL of aqueous 20.0 wt.-%sodium dodecyl sulfate (SDDS) (12.40 mmol), 8.0 mL of aqueous 5.0 wt.-%sodium bicarbonate (NaHCO₃) (3.75 mmol), and 8.0 mL of aqueous 5.0 wt.-%potassium persulfate (0.5 mol.-% to VBC) was added to a 500 mLround-bottom flask. This mixture was cooled to 0° C. for 1 h, afterwhich 5.65 mL of aqueous 5.0 wt.-% sodium metabisulfite (0.5 mol.-% toVBC) was added. The solution was sparged with nitrogen for 15 min. Theflask was closed with a rubber septum and placed in an oil bath at 30°C. for 3 h. After that time, the polymer was precipitated in 1500 mL ofmethanol, filtered and dried in vacuo. (47.5 g, 95%), (GPC: Mw=733 k,PDI=6.3 vs. polyacrylic acid narrow standards), ¹H NMR (DMSO-d6): δ7.30-δ 6.20 (broad, 4H, aromatic), δ 4.75-δ 4.30 (broad, 2H, benzylicCH₂), δ 2.40-δ 0.90 (broad, 3H, backbone CH, CH₂).

Example 17 Poly(t-BuOS) Procedure A

8.79 g of t-butoxystyrene (t-BuOS) (46.3 mmol), 23.3 mL deionized water,3.82 mL of aqueous 20.0 wt.-% sodium dodecyl sulfate (SDDS) (2.48 mmol),1.83 mL of aqueous 5.0 wt.-% sodium bicarbonate (NaHCO₃) (0.86 mmol),and 1.29 mL of aqueous 5.0 wt.-% potassium persulfate (0.5 mol.-% tot-BuOS) was added to a 100 mL round-bottom flask. This mixture wascooled to 0° C. for 1 h, after which 0.92 mL of aqueous 5.0 wt.-% sodiummetabisulfite (0.5 mol.-% to t-BuOS) was added. The solution was spargedwith nitrogen for 15 min. The flask was closed with a rubber septum andplaced in an oil bath at 30° C. for 3 h. After that time, the polymerwas precipitated in 300 mL of methanol, filtered and dried in vacuo.(6.15 g, 70%), (GPC: Mw=1200 k, PDI=10.0 vs. polystyrene narrowstandards), ¹H NMR (DMSO-d6): δ 6.75-δ 6.20 (broad, 4H, aromatic), δ2.13-δ 0.80 (broad, 12H, backbone CH, CH₂, t-butyl CH₃).

Example 18 Poly(t-BuOS) Procedure B

The polymerization was carried out in identical fashion as described for‘Procedure A’ (Example 17) except 1.0 mol.-% of initiator vs. t-BuOS wasused: ie. 2.58 mL of aqueous 5.0 wt.-% potassium persulfate, 1.84 mL ofaqueous 5.0 wt.-% sodium metabisulfite. (GPC: Mw=700 k, PDI=5.0 vs.polystyrene narrow standards), ¹H NMR (DMSO-d6): δ 6.75-δ 6.20 (broad,4H, aromatic), δ 2.13-δ 0.80 (broad, 12H, backbone CH, CH₂, t-butylCH₃).

Example 19 Poly(t-BuOS) Procedure C

The polymerization was carried out in identical fashion as described for‘Procedure A’ (Example 17) except 1.5 mol.-% of initiator vs. t-BuOS wasused: ie. 3.87 mL of aqueous 5.0 wt.-% potassium persulfate, 2.76 mL ofaqueous 5.0 wt.-% sodium metabisulfite. (GPC: Mw=185 k, PDI=4.0 vs.polystyrene narrow standards), ¹H NMR (DMSO-d6): δ 6.75-δ 6.20 (broad,4H, aromatic), δ 2.13-δ 0.80 (broad, 12H, backbone CH, CH₂, t-butylCH₃).

Example 20 Poly(Acetoxystyrene)

10.0 g of acetoxystyrene (AcS) (Aldrich, 96%), 29.0 mL deionized water,3.33 mL of aqueous 20.0 wt.-% sodium dodecyl sulfate (SDDS) (2.48 mmol),1.6 mL of aqueous 5.0 wt.-% sodium bicarbonate (NaHCO3) (0.75 mmol), and1.6 mL of aqueous 5.0 wt.-% potassium persulfate (0.5 mol.-% to AcS) wasadded to a 100 mL round-bottom flask. This mixture was cooled to 0° C.for 1 h, after which 1.13 mL of aqueous 5.0 wt.-% sodium metabisulfite(0.5 mol.-% to AcS) was added. The solution was sparged with nitrogenfor 15 min. The flask was closed with a rubber septum and placed in anoil bath at 30° C. for 3 h. After that time, the polymer wasprecipitated in 300 mL of methanol, filtered and dried in vacuo. (9.50g, 95%), (GPC: Mw=554 k, PDI=4.0 vs. polyacrylic acid narrow standards),¹H NMR (DMSO-d6): δ 7.00-δ 6.25 (broad, 4H, aromatic), δ 2.38-δ 2.00(broad, 3H, acetyl CH₃), δ 2.05-δ 1.00 (broad, 3H, backbone CH, CH₂).

Example 21 Poly(NaVBS-co-VBA)

Vinylbenzyl alcohol (207 g, 1.39 mol) was added to a solution of sodiumvinylbenzylsulfonate (NaVBS, 1058 g, 2.49 mol, 51.9% monomer, 35.1%water, 13% iodide impurity) in deionized water (8766 g) at 35° C. Themixture was sparged with nitrogen for 0.5 h. Vazo 56WSP (2.71 g, 10.0mmol, DuPont) was added toward the end of the sparging period. Thereaction mixture was heated to 80° C. and stirred under nitrogen for 3.5h. A second charge of Vazo 56WSP (1.35 g, 5.00 mmol) was added after 3.5h of reaction time, and the polymerization was continued for another 2h. Following the polymerization, the solution was kept at 80° C. andpurged with nitrogen in order to reduce the volume by about 50%. Thepolymer was precipitated from acetone. The percent conversion of NaVBSto polymer was estimated gravimetrically and spectrophotometrically (95%conversion). ¹H NMR (D₂O): δ 7.16 (broad, 2H, aromatic), δ 6.63 (broad,2H, aromatic), δ 4.43 (broad, 0.4H, benzyl alcohol CH₂), δ 4.08 (broad,1.6H, benzylsulfonate CH₂), δ −0.75-2.75 (broad, 3H, backbone CH, CH₂).

Example 22 Poly(NaVBS-co-HEMA)

9.30 g (42.2 mmol) of NaVBS was dissolved in water at 40° C. in a 250 mLround bottom flask. This solution was purged with nitrogen for 15 min.1.22 g (9.39 mmol) of 2-hydroxyethyl methacrylate (HEMA) and 34.11 mg(0.1258 mmol) of VAZO 56WSP were added to the solution. The mixture washeated for 24 h at 85° C. The polymer was precipitated in 875 ml ofacetone and dried in vacuo. (Yield 9.22 g, 92%) Gel PermeationChromatography indicated high molecular weight (280 k, vs. polystyrenesulfonate narrow standards). ¹H NMR (D₂O): δ 7.50-δ 6.25 (broad, 4H,aromatic), δ 4.25-δ 3.75 (broad, 2H, benzylic), δ 3.60-δ 2.80 (broad,1.08H, ethyl CH₂), δ 2.50-δ 1.00 (broad, backbone CH, CH₂), δ 1.0-δ 0.20(broad, 0.84H, CH₃). 22% incorporation of HEMA calculated from ¹H NMRdata.

Example 23 Poly(NaVBS-co-1-VPE)

A 250 ml round-bottom flask was charged with 6.60 g NaVBS (30.0 mmol),2.96 g 1-VPE (20.0 mmol), 27.0 mg Vazo 56WSP (0.10 mmol), 66.0 ml waterand a stir bar. The mixture was bubbled with nitrogen for 15 min., theflask was closed with rubber septa and put into an oil bath at 80° C.with vigorous stirring for 24 h. The reaction mixture was then slowlyprecipitated into 300 ml of acetone with vigorous stirring. The whiteprecipitate was filtered and washed with acetone and dried in vacuo.(7.90 g, 83%, Mw=45 k, PDI=2.25 vs. sulfonated polystyrene narrowstandards). ¹H NMR (D₂O): δ 8.25-δ 5.50 (broad, 4H, aromatic), δ 4.50-δ3.50 (broad, 1.44H, benzylic), δ 2.75-δ 0.25 (broad, backbone CH CH₂,C—CH₃).

Example 24 Poly(NaVBS-co-2-VPE)

A 250 ml round-bottom flask was charged with 13.20 g NaVBS (60.0 mmol),4.44 g 2-VPE (30.0 mmol), 54.0 mg Vazo 56WSP (0.2 mmol) 133 mL water,and a stir bar. The mixture was sparged with nitrogen for 15 min., thenclosed with rubber septa and put into an oil bath at 80° C. withvigorous stirring for 24 h. The reaction mixture was then slowlyprecipitated into 500 ml of acetone with vigorous stirring. The whiteprecipitate was filtered, washed with acetone, and dried in vacuo. (16.0g, 91%, Mw=47.6 k, PDI=2.1 vs. sulfonated polystyrene narrow standards).¹H NMR (D₂O): δ 8.25-δ 5.50 (broad, 4H, aromatic), δ 4.60-δ 3.20 (broad,2H, benzylic and CH₂—O), δ 3.20-δ 2.30 (broad, benzylic CH₂—C), δ 2.30-d0.25 (broad, backbone CH₂ and CH).

Example 25 Poly(NaSS-co-VBA)

A 500 ml round-bottom flask was charged with 27.9 g NaSS (135.3 mmol),8.1 g VBA (60.2 mmol), 109 mg Vazo 56WSP (0.4 mmol) 396 mL water, and astir bar. The mixture was sparged with nitrogen for 15 min., then closedwith rubber septa and heated at 80° C. with vigorous stirring for 24 h.The reaction mixture was then slowly precipitated into 500 ml of acetonewith vigorous stirring. The white precipitate was filtered, washed withacetone, and dried in vacuo. (22 g, 64 mol-% of sulfonated monomer,Mw=237 k, PDI=2.6 vs. sulfonated polystyrene narrow standards). ¹H NMR(D₂O): δ 7.84-δ 5.85 (broad, aromatic), δ 4.60-δ 4.06 (broad, 2H,benzylic CH₂—O), δ 2.50-

0.50 (broad, backbone CH₂ and CH).

Example 26 Poly(NaSS-co-HEMA)

A 500 ml round-bottom flask was charged with 27.9 g NaSS (135.3 mmol),8.1 g HEMA (60.2 mmol), 109 mg Vazo 56WSP (0.4 mmol) 396 mL water, and astir bar. The mixture was sparged with nitrogen for 15 min., then closedwith rubber septa and heated at 80° C. with vigorous stirring for 24 h.The reaction mixture was then slowly precipitated into 500 ml of acetonewith vigorous stirring. The white precipitate was filtered, washed withacetone, and dried in vacuo. (39.4 g, 64 mol-% of sulfonated monomer %,Mw=457 k, PDI=3.7 vs. sulfonated polystyrene narrow standards). ¹H NMR(D₂O): δ 7.90-δ 5.95 (broad, aromatic), δ 3.72-δ 2.86 (broad, 4H,O—CH₂—CH₂—OH), δ 2.13-δ 0.05 (broad, backbone CH₃, CH₂ and CH).

Example 27 Poly(NaSS)

A 500 ml round-bottom flask was charged with 13.8 g NaSS (66.9 mmol),109 mg Vazo 56WSP (0.4 mmol) 196 mL water, and a stir bar. The mixturewas sparged with nitrogen for 15 min., then closed with rubber septa andheated at 80° C. with vigorous stirring for 24 h. The reaction mixturewas then slowly precipitated into 500 ml of acetone with vigorousstirring. The white precipitate was filtered, washed with acetone, anddried in vacuo. (10 g, Mw=490 k, PDI=3.6 vs. sulfonated polystyrenenarrow standards). ¹H NMR (D₂O): δ 7.94-δ 5.94 (broad, aromatic), δ2.10-δ 0.22 (broad, backbone CH2 and CH).

Example 28 Poly(2-acrylamido-2-methylpropane sulfonic acid) (p(AMPS))

A 1000 ml cylindrical reactor was equipped with reflux condensor,mechanical stirrer and charged with 50.0 mL of deionized water andheated to 75° C. 151.6 g AMPS, 545.2 mL water, were stirred together ina separate vessel until the AMPS was fully dissolved. The reactor andAMPS solution were sparged with nitrogen for 15 min. 446 mg Vazo 56WSPwas separately dissolved in 9.47 g of water. The AMPS and Vazo 56WSPsolutions were fed slowly into the reactor over a period of 1 hmaintaining the reaction temperature at 75° C. with vigorous stirring.The reaction was stirred at 75° C. for and additional 2 h. The finalreaction mixture was cooled to room temperature. The mixture wasobserved to be extremely viscous, indicating the presence of highmolecular weight polymer.

(Co)Polymer Syntheses (Post-Polymerization Modifications) Example 29Sulfoethylated p(VBC)

1.0 g of poly(vinylbenzyl chloride) (p(VBC)) was dissolved in 99.0 g ofanhydrous dimethylsulfoxide (DMSO) in a 250 mL round-bottom flaskequipped with an addition funnel and magnetic stirring under nitrogen.Separately, 1.068 g (1.1 eq. to Cl) of sodium isethionate (NaISA) wasdissolved in 19.0 g DMSO under nitrogen. In a third vessel, 0.165 g(1.05 eq. to Cl) of sodium hydride (NaH) was added to 3.1 g DMSO undernitrogen and stirred to form a slurry. The NaH slurry was then added toa 250 mL round-bottom flask under nitrogen purge and magnetic stirring.The NaISA solution was then added slowly with rapid stirring. TheNaH/NaISA mixture (disodium isethionate) was stirred at room temperaturefor 30 min. until the evolution of gas has ceased. This mixture was thenquickly transferred to the addition funnel of the p(VBC) reactor. Thedisodium isethionate solution was then slowly added to the p(VBC)solution with rapid stirring. This mixture was stirred for an additional18 h at room temperature. After that time, 1.0 mL of 5.0 v/v % aqueoushydrochloric acid was added. The solution was then slowly poured into 1L of tetrahydrofuran with rapid stirring forming a white precipitate.The precipitate was filtered, redissolved in 100 mL of deionized waterand slowly poured into 800 mL of tetrahydrofuran. The white polymerpowder was collected by filtration and dried in vacuo. ¹H NMR (D₂O): δ7.40-δ 5.75 (broad, 4H, aromatic), δ 4.60-δ 4.00 (broad, 2H, benzylic),δ 4.00-δ 3.30 (broad, 2H, ethyl —CH₂—SO₃), δ 3.25-δ 2.80 (broad, 2H,ethyl —O—CH₂—C), δ 2.25-δ 0.75 (broad, 3H, backbone CH2, CH).

Example 30 Sulfopropylated p(VBC)

1.0 g of poly(vinylbenzyl chloride) (p(VBC)) was dissolved in 99.0 g ofanhydrous dimethylsulfoxide (DMSO) in a 250 mL round-bottom flaskequipped with an addition funnel and magnetic stirring under nitrogen.Separately, 2.13 g (2.0 eq. to Cl) of sodium 3-hydroxypropane sulfonate(NaHPS) was dissolved in 42.5 g anhydrous DMSO under nitrogen. In athird vessel, 0.3464 g (2.2 eq. to Cl) of sodium hydride (NaH) was addedto 5.0 g DMSO under nitrogen and stirred to form a slurry. The NaHslurry was then added to a 250 mL round-bottom flask under nitrogenpurge and magnetic stirring. The NaHPS solution was then added slowlywith rapid stirring. The NaH/NaHPS mixture (disodiumhydroxypropanesulfonate) was stirred at room temperature for 30 min.until the evolution of gas had ceased. This mixture was then quicklytransferred to the addition funnel of the p(VBC) reactor. The disodiumhydroxypropandsulfonate solution was then slowly added to the p(VBC)solution with rapid stirring. This mixture was stirred for an additional18 h at room temperature. After that time, 1.0 mL of 5.0 v/v % aqueoushydrochloric acid was added. The solution was then slowly poured into 1L of acetone with rapid stirring forming a white precipitate. Theprecipitate was filtered, redissolved in 100 mL of deionized water andslowly poured into 800 mL of acetone. The white polymer powder wascollected by filtration and dried in vacuo. ¹H NMR (D₂O): δ 7.40-δ 5.75(broad, 4H, aromatic), δ 4.60-δ 4.20 (broad, 2H, benzylic), δ 4.20-δ3.50 (broad, 2H, propyl-O—CH₂—), δ 3.10-δ 2.60 (broad, 2H, propyl—CH₂—SO₃), δ 2.25-δ 1.75 (broad, 2H, propyl-C—CH₂—C), δ 1.50-δ 0.50(broad, 3H, backbone CH—CH₂).

Example 31 Conversion of p(tBuOS) to poly(vinylphenol)

2.0 g of p(t-BuOS) (Mw˜1200 k, PDI=10.0) was dissolved in 62.0 g of1,4-dioxane in a 250 mL round bottom flask. To that solution was added17.9 g of concentrated hydrochloric acid (37.0 wt.-% in water). Themixture was stirred at 80° C. under nitrogen for 4 h. The reactionsolution was then poured into 400 mL of water. This slurry wasneutralized to pH=7 by addition of a 5.0 wt.-% aqueous sodium hydroxidesolution. The polymer powder was filtered and dried in vacuo. (1.30 g,95%, Mw=600 k, PDI=8.0 vs. poly(acrylic acid) narrow standards). ¹H NMR(DMSO-d6): δ 9.10-δ 8.80 (broad, 1H, OH), δ 6.75-δ 6.20 (broad, 4H,aromatic), δ 2.20-δ 0.90 (broad, backbone CH, CH₂).

Example 32 Conversion of p(acetoxystyrene to poly(vinylphenol)

1.0 g of poly(acetoxystyrene) (6.16 mmol acetoxy groups) was dissolvedin 37.7 mL of 1,4-dioxane at room temperature. To this rapidly stirredsolution was added a solution of 2.47 g of sodium hydroxide (61.7 mmol)in 19.3 mL of deionized water. The reaction mixture was then heated to40° C. for 4 h. The resulting mixture was cooled to room temperature andacidified with and excess of 5.0 v/v % aqueous hydrochloric acid. Theprecipitated polymer was washed with deionized water several times anddried in vacuo. (0.73 g, 98%, Mw=630 k, PDI=5.0 vs. poly(acrylic acid)narrow standards). ¹H NMR (DMSO-d6): δ 9.10-δ 8.80 (broad, 1H, OH), δ6.75-δ 6.20 (broad, 4H, aromatic), δ 2.20-δ 0.90 (broad, backbone CH,CH₂).

Example 33 Sulfopropylation of poly(vinylphenol) (pVPh)

1.0 g of pVPh (Mw˜600 k, PDI˜4.0) was dissolved in 19.0 g of anhydrousdimethylsulfoxide (DMSO) in a 100 mL round-bottom flask equipped with anaddition funnel and magnetic stirring under nitrogen. Separately, 1.88 g(1.0 eq. to OH) of sodium 3-bromopropane sulfonate (NaBPS) was dissolvedin 5.64 g anhydrous DMSO under nitrogen. In a third vessel, 0.220 g (1.1eq. to OH) of sodium hydride (NaH) was added to 5.0 g DMSO undernitrogen and stirred to form a slurry. The NaH slurry was then added toa 250 mL round-bottom flask under nitrogen purge and magnetic stirring.The pVPh solution was then added slowly with rapid stirring. TheNaH/pVPh mixture (poly(sodium vinylphenolate)) was stirred at roomtemperature for 30 min. until the evolution of gas had ceased. The NaBPSsolution was then quickly added and stirred at room temperature for 18h. The solution was then slowly poured into 500 mL of acetone with rapidstirring forming a white precipitate. The white polymer powder wascollected by filtration and dried in vacuo. (2.0 g, 91%), ¹H NMR (D₂O):δ 7.10-δ 5.90 (broad, 4H, aromatic), δ 4.10-δ 3.80 (broad, 2H, propyl--—O—CH₂—), δ 2.90-δ 2.50 (broad, 2H, propyl —CH₂—SO₃), δ 2.20-δ 1.80(broad, 2H, propyl-C—CH₂—C), δ 2.00-δ 0.50 (broad, 3H, backbone CH—CH₂).

Ion-Exchange of Salt-Form (Co)Polymers to Protonated (Co)PolymersGeneral procedure for many types of water-soluble, acidic polymers insalt-form Example 34 Small-Scale Ion-Exchange

To a glass column (7.5 cm in diameter, 24 cm in length) was added Dowex®Marathon C ion-exchange resin (approx. 300 g). This column was rinsedexhaustively with deionized water then charged with a 10 wt. % solutionof poly(sodium vinylbenzylsulfonate-co-vinylbenzyl alcohol) (47.49 g) indeionized water (191.2 g). The eluent was collected in fractions, whichwere tested with pH strips in order to determine presence of protonatedpolymer. Fractions containing polymer were combined to yield a 3%solution of poly(vinylbenzylsulfonic acid-co-vinylbenzyl alcohol) (38.6g, 90%), 99+% exchange efficiency (H⁺ for Na⁺) by elemental analysis andacid-base titration with NaOH to phenolphthalein endpoint.

Example 35 Large-scale Ion-exchange

A glass column (30.5 cm in diameter, 122 cm in length) was equipped witha compressed nitrogen line (25 psi max. pressure) and deionized waterinlet. Dowex® Marathon C ion-exchange resin (21.74 L, wet) was thenadded. This column was rinsed exhaustively with deionized water thencharged with a 20 wt. % solution of poly(sodiumvinylbenzylsulfonate-co-vinylbenzyl alcohol) (3970 g) in deionized water(14.0 kg). The solution was forced through the column with nitrogenoverpressure (up to 17 psig) at a rate of 0.4 bed volumes per hour andeluent was collected in fractions. The pH of the eluent was continuouslytested with pH test strips in order to determine the presence ofprotonated polymer. Fractions containing the highest concentrations ofpolymer were combined to yield a 17.5 wt. % solution ofpoly(vinylbenzylsulfonic acid-co-vinylbenzyl alcohol) (2540 g, 69%) with99.8% exchange efficiency (H⁺ for Na⁺) by elemental analysis andacid-base titration with NaOH to phenolphthalein endpoint.

TAAOH Neutralization of Protonated Polyelectrolyte Solutions Example 36Tetrabutylammonium hydroxide neutralization of Poly(Styrenesulfonicacid)

15.00 g of a 30 wt. % poly(styrenesulfonic acid) (purchased fromPolyscience, MW=70 kg/mol) aqueous solution was combined with 9.22 g of55 wt. % tetrabutylammonium hydroxide (TBAOH) aqueous solution andallowed to stir at room temperature for 60 minutes. 15.03 g of NMP wasthen added to the neutralized polyelectrolyte solution. The neutralizedpolyelectrolyte solution was then heated to 60° C. in vacuo to removethe water. This resulted in a 38 wt. % solution of TBAOH-neutralizedpoly(styrenesulfonate) in NMP with residual water content of no morethan 0.2 wt. %.

Example 37 Tetrabutylammonium hydroxide neutralization ofPoly(Styrenesulfonate-co-vinylbenzyl alcohol)

153.94 g of a 2.6 wt. % poly(styrenesulfonic acid-co-vinylbenzylalcohol) (MW=237 kg/mol, 70 wt. % styrene sulfonic acid) aqueoussolution was combined with 6.79 g of 55 wt. % TBAOH aqueous solution andallowed to stir at room temperature for at least 60 minutes. 30.0 g ofNMP was then added to the neutralized polyelectrolyte solution. Theneutralized polyelectrolyte solution was then heated to 60° C. in vacuoto remove the water. This resulted in a 20 wt. % solution ofTBAOH-neutralized poly(styrenesulfonate-co-vinyl benzyl alcohol) in NMPwith residual water content of no more than 0.7 wt. %.

Example 38 Tetrabutylammonium hydroxide neutralization ofPoly(Vinylbenzyl sulfonic acid-co-hydroxyethyl methacrylate)

7.03 g of a 12.2 wt. % poly(vinylbenzylsulfonic acid-co-hydroxyethylmethacrylate) (MW 190 kg/mol, 79 wt. % VBS) aqueous solution wascombined with 1.56 g of 55 wt. % TBAOH aqueous solution and allowed tostir at room temperature for at least 60 minutes. 6.91 g of NMP was thenadded to the neutralized polyelectrolyte solution. The neutralizedpolyelectrolyte solution was then heated to 60° C. in vacuo to removethe water. This resulted in a 27 wt. % solution of TBAOH-neutralizedpoly(VBS-co-hydroxyethyl methacrylate) in NMP.

Example 39 TPAOH neutralization of Poly(Vinylbenzyl sulfonicacid-co-vinylbenzyl alcohol)

24.02 g of a 16.8 wt. % poly(VBS-co-vinylbenzyl alcohol) (MW=60 kg/mol,86 wt. % VBS) aqueous solution was combined with 8.31 g of 40.9 wt. %tetrapropylammonium hydroxide (TPAOH) aqueous solution and allowed tostir at room temperature for at least 60 minutes. 29.74 g of NMP wasthen added to the neutralized polyelectrolyte solution. The neutralizedpolyelectrolyte solution was then heated to 60° C. in vacuo to removethe water. This resulted in a 20 wt. % solution of TPAOH-neutralizedpoly(VBS-co-vinyl benzyl alcohol) in NMP.

Example 40 TBAOH neutralization of Poly(Vinylbenzyl sulfonicacid-co-vinylbenzyl alcohol)

72.31 g of a 13.9 wt. % poly(vinylbenzyl sulfonic acid-co-vinylbenzylalcohol) (MW=260 kg/mol, 85 wt. % VBS) aqueous solution was combinedwith 19.26 g of 55 wt. % TBAOH aqueous solution and allowed to stir atroom temperature for at least 60 minutes. 79.36 g of NMP and 143.86 g ofacetonitrile was then added to the neutralized polyelectrolyte solution.The neutralized polyclectrolyte solution was then heated to 60° C. invacuo to remove the water by azeotropic distillation. This resulted in a20 wt. % solution of TBAOH-neutralized poly(vinylbenzylsulfonate-co-vinyl benzyl alcohol) in NMP with residual water content ofno more than 0.09 wt. %.

Example 41 TBAOH neutralization of Poly(2-acrylamido-2-methylpropanesulfonate)

17.25 g of 20.1 wt. % poly(2-acrylamido-2-methylpropane sulfonate)aqueous solution (MW=120 kg/mol) was combined with 6.35 g of 55% TBAOHaqueous solution and allowed to stir at room temperature for at least 60minutes. 15.35 g of NMP was then added to the neutralizedpolyelectrolyte solution. The neutralized polyelectrolyte solution wasthen is heated to 60° C. in vacuo to remove the water. This resulted ina 35 wt. % solution of TBAOH-neutralizedpoly(2-acrylamido-2-methylpropane sulfonate) in NMP.

Example 42 TBAOH neutralization of Poly(acrylic acid)

A poly(acrylic acid) acid solution was prepared by dissolving 4.98 g ofpoly(acrylic acid) (MW=450 kg/mol) into 81.40 g of NMP. The poly(acrylicacid) was purchased from Sigma-Aldrich as used as received. 7.58 g ofthe poly(acrylic acid) solution was combined with 0.649 g of 55 wt. %TBAOH aqueous solution and allowed to stir at room temperature for atleast 60 minutes.

Example 43 TBAOH Neutralization of spPVA

15.7 g of a 10.9 wt. % aqueous solution sulfopropylated PVA (MW=144kg/mol, 56 mole % sulfonation) was combined with 3.84 g of 55% TBAOHaqueous solution in a vial and allowed to stir at room temperature forat least 60 minutes. 8.04 g of NMP was then added to the neutralizedpolyelectrolyte solution. The neutralized polyclectrolyte solution wasthen heated to 60° C. in vacuo to remove the water. This resulted in a31 wt. % solution of TBAOH-neutralized sulfopropylated poly(vinylalchohol) in NMP with residual water content of no more than 0.2 wt. %.

Blending of Neutralized Polyelectrolyte Solutions with Matrix CopolymersExample 44 TBAOH neutralized Poly(Styrenesulfonate) with Kynar® PVDF

24.36 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 10.08 g of 38 wt. % TBAOH-neutralizedpoly(styrenesulfonate) from Example 36 and stirred at room temperaturefor four hours before membrane casting.

Example 45 TBAOH neutralized Poly(Styrenesulfonate) with Kynar® PVDF

18.99 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 14.17 g of 20 wt. % TBAOH-neutralizedpoly(styrenesulfonate-co-vinylbenzyl alcohol) from Example 37 andstirred at room temperature for four hours. To this solution was added0.9973 g of Desmodur N 3300A cross-linking agent (aliphaticpolyisocyanate from Bayer) and stirred for 2 hours at room temperaturebefore membrane casting.

Example 46 TBAOH neutralized Poly(VBS-co-hydroxylethyl methacrylate)with Kynar® PVDF

10.73 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 6.16 g of 27 wt. % TBAOH-neutralizedpoly(styrenesulfonate-co-vinylbenzyl alcohol) from Example 38 andstirred at room temperature for four hours. To this solution was added0.7135 g of Desmodur BL 3175A cross-linking agent (blocked aliphaticpolyisocyanate from Bayer) and 0.030 g of Fascat 4202 (dibutyltindilaurate from Arkema Inc.). The solution was stirred for 2 hours atroom temperature before membrane casting.

Example 47 TPAOH neutralized Poly(VBS-co-VBA) with Kynar® PVDF

13.69 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 8.03 g of 20 wt. % TPAOH-neutralizedpoly(styrenesulfonate-co-vinylbenzyl alcohol) From Example 39 andstirred at room temperature for four hours. To this solution was added0.85 g of Desmodur BL 3175A cross-linking agent and 0.026 g of Fascat4202. The solution was then stirred for 2 hours at room temperaturebefore membrane casting.

Example 48 TBAOH neutralized Poly(VBS-co-VBA) with Kynar® PVDF

12.96 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 11.12 g of 20 wt. % TBAOH-neutralizedpoly(styrenesulfonate-co-vinylbenzyl alcohol) from Example 40 andstirred at room temperature for four hours. To this solution was added0.3420 g of Desmodur N 3300A cross-linking agent. The solution wasstirred for 2 hours at room temperature before membrane casting.

Example 49 TBAOH neutralized Poly(2-acrylamido-2-methylpropanesulfonate) with Kynar® PVDF

43.06 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. %PVDF) was combined with 19.3 g of 35 wt. % TBAOH-neutralizedpoly(2-acrylamido-2-methylpropane sulfonate) from Example 41 and stirredat room temperature for four hours before membrane casting.

Example 50 TPAOH neutralized Poly(acrylic acid) with Kynar® PVDF

5.30 g of a solution containing Kynar® 2801 and NMP (15 wt. % polymer)was then blended with 8.23 g of neutralized poly(acrylic acid) solutionfrom Example 42 for four hours at room temperature before membranecasting.

Example 51 TBAOH neutralized spPVA with Kynar® PVDF

4.72 g of a solution containing Kynar® PVDF 2801 and NMP (15 wt. % PVDF)was combined with 5.5 g of 31 wt. % TBAOH-neutralized sulfopropylatedpoly(vinyl alcohol) from Example 43 and stirred at room temperature forfour hours. To this solution was added 0.290 g of Desmodur N 3300Across-linking agent. The solution was stirred for 2 hours at roomtemperature before membrane casting.

Drying of Polymer Blend Solutions

Example 52

Casting of the polymer blend solutions into membranes described inExamples 44-51 was done using a Mathis LTE Labdryer. Aluminum foil withapproximate dimensions of 15×12 in² was used as the substrate forcasting. Approximately 15 g of polymer solution was spread onto the foiland drawn down to a wet film thickness of about 300 μm using a doctorblade. The resulting thin films was then heated at 177° C. for 7 minwith an air flow of 1800-2300 RPM. The dry membranes were then removedfrom the oven and cooled to room temperature. All polymer blend solutioncompositions produced membranes that had a dry film thickness between25-50 μm.

Washing and Acidification of Polyelectrolyte/Matrix (Co)Polymer BlendFilms

Example 53

The membranes cast on aluminum foil in Example 52 were immersed in 18 MΩdeionized water to release them from the substrate. The free-standingmembranes were then immersed in a 1M aqueous hydrochloric acid bath at60-65° C. for 120 min. Subsequently, they were washed with deionizedwater and immersed in a 1M aqueous sulfuric acid at 60-65° C. for 120min. The membranes were then removed from the sulfuric acid bath andwashed with 18 MΩ deionized water to remove residual acid. The acid-formmembranes were then air dried and stored at room temperature for futureuse.

Preparation of Membrane-Electrode Assemblies General procedure for thepreparation of membrane-Electrode Assemblies (MEAs) from many types ofpolyelectrolyte/matrix (co)polymer blend films produced by themethodologies discussed above Example 54

Commercially-available electrodes and gaskets are cut to appropriatesize/shape to fit in the testing cell. There should be no gaps and/oroverlap of electrodes and gaskets. One electrode and gasket each areplaced onto a stainless steel hot-pressing plate/insert. The surface ofthe electrode is then wetted with deionized water A piece of wetmembrane is then placed over the electrode surface and smoothed out. Alayer of deionized water down is then applied to the upper membranesurface and the second electrode is placed on this layer. The electrodesare aligned and excess water gently squeezed out. The second gasket isplaced on top of the MEA, followed by insert and top pressing plate. Theentire assembly is then placed into a pre-heated press at apredetermined time and temperature. It is then removed and cooled toroom temperature under low pressure (1-2 lbs.). The MEA is carefullyremoved from the stainless steel pressing plates (the membrane may stickto the insert slightly) and excess membrane/gasket material is trimmedaway. The complete MEA is placed in the testing cell and bolts aretightened with an appropriate, predetermined force.

1. A polymer blend composition having no readily hydrolysable groupscomprising: a) a polyelectrolyte copolymer having the general formula:

wherein: n=greater than or equal to 1 percent m=less than or equal to 99percent L=non-perfluorinated alkyl or alkylene-ether linkage L′=a bondor alkyl or alkylene-ether linkage A=a sulfonate, phosphonate orcarboxylate B=a group capable of cross-linking, selected from the groupconsisting of hydroxyl; primary, secondary, and tertiary amines:N-methylol acrylamide; isobutoxy methacrylamide;N-methylenebisacrylamide; allyl groups; styryl groups; glycidylmethacrylate; free and blocked isocyanates, melamines, epoxies,carboxylates, α,ω-dihaloalkanes, α,ω-dialdehydes, carboxylic acids,alkoxy silanes, silicones, aziridines, and carbodiimides; and b) amatrix polymer.
 2. The polymer blend of claim 1 wherein n is greaterthan 70% and m is less than 30%.
 3. The polymer blend of claim 1 whereinsaid matrix polymer comprises a fluoropolymer.
 4. The polymer blend ofclaim 1 wherein the polyelectrolyte copolymer is present in domain sizesof less than 500 nm.
 5. The polymer blend of claim 4 wherein saidpolyelectrolyte domain sizes are from 1 nm to 100 nm.
 6. The polymerblend of claim 1 wherein said group capable of crosslinking (B) is ahydroxyl group.
 7. The polymer blend of claim 1 wherein said group (A)is a sulfonate group.
 8. The polymer blend of claim 1 wherein saidpolyelectrolyte copolymer (a) is an tetraalkylammonium salt.
 9. Thepolymer blend of claim 1, wherein said polyelectrolyte copolymercontains as the monomer units at over 1 mole % a vinyl etherfunctionalized with a C₂₋₆ alkyl sulfonate, alkyl phosphonate or alkylcarboxylate.
 10. The polymer blend of claim 9, wherein saidpolyelectrolyte copolymer contains as the monomer units at over 1 mole %a vinyl ether functionalized with a C₃₋₄ alkyl sulfonate, alkylphosphonate or alkyl carboxylate.
 11. The polymer blend of any of claim1, wherein said polyelectrolyte copolymer contains as the monomer unitsat over 1 mole % a poly(vinyl alcohol) alcohol functionalized with aC₂₋₆ alkyl sulfonate, alkyl phosphonate or alkyl carboxylate.